Sterling Siren

[Jean-Marc Dugas]

Question for our siren experts.

I picked up a Sterling siren model 12, serial No 7933 today. What can you tell us about this unit?

[Jean-Marc Dugas]

Couple of pics of my new siren. It will go under the hood until I can find a B&M to go on the roof.

This is a 6 volts unit. Are there any voltage reducers that I can use with it or are we OK with 12 volts since it will not see heavy use?

http://www.professionalcarsociety.org/forums/picture.php?albumid=5&pictureid=82

http://www.professionalcarsociety.org/forums/picture.php?albumid=5&pictureid=83

[Kevin O'Connell]

Functionally, the No. 12 is the predecessor to the No. 20. They use the same motor. Sterling's corporate records were hit and miss so there's no certain way of determining when anything was introduced except the Oscillite. Somewhere I have a photocopy of their Corporate Record book covering about thirty years, beginning with their relocation to Rochester. You'd think such a document would be a treasure trove but alas, there's precious little useful information.

The No. 12 is a beautiful instrument. Early versions were nickel plated, later versions chrome plated. Compared to a more serious instrument, however, a No. 12 is more of a relic.

Normally I would advise you not to worry about the voltage of the motor as 6 volt motors generally perform well at 12 volts. With Sterling products I'm only willing to say that about the No. 30. The armature on smaller Sterling sirens is just too flimsy to safely overspeed.

Keep the faith, I think a Super Chief is in your not-too-distant future....

[Richard Vyse]

That is a very neat looking siren.

Richard

[John ED Renstrom]

Keven, on this type of siren the horn is were the air comes in and the sound goes out the side holes? am I right on that? if that were the case this could be mounted behind the grill with the horn down with out effection the direction of the noise. of course its placment would do that, but who gets to operate in free space.

[Jean-Marc Dugas]

Great question John. I was wondering the same thing.

[Kevin O'Connell]

Sorry about the delayed response- I don't get to splurge on the internet as much as I'd like to these days.

You are correct. Air enters the front of the siren and is pumped out the ports. As the rotor turns, the ports close and the air is compressed. When the ports open the compressed air "pops" from the port. At higher speeds the frequency of the pop increases to the shrill sound that we're all familiar with. Not all of the sound emits from the ports, however. Some of what you hear is resonance from the intake.

When mounting a real siren it is imperative that the inlet face forward. Vertical or sideways mounting causes wind shear which starves the air inlet, compromising siren performance.

[Jean-Marc Dugas]

Thanks for the info.